The invention relates to an apparatus and a method for joining a pipe conduit to a drilling device, expanding device or pull-in device or the like.
During trenchless pipe laying, new pipes are pulled into a bore in the soil. The bore may be a new bore produced during the pulling-in or an already existing pilot bore which is widened to the desired diameter by an expanding device. Furthermore, expanding devices—what are referred to as bursting devices—are used in order to destroy a laid old line and to pull in a new line in its place.
The new pipes to be laid are often joined directly to the advanced tool, so that the bore is produced or widened and the new pipe pulled in in one operation.
New pipes are very often laid from a starting shaft. Since there is a very restricted space in such a shaft, new pipe conduits which consist of individual short pipes and are pulled in one after the other are mainly used.
The pulling force which is produced by the leading tool in combination with the shell friction between the components and the earth leads to a tensile stress in the new pipe. The result of this is that a new pipe conduit consisting of such individual short pipes is pulled apart or an individual, long new pipe is stretched to a considerable degree.
It is therefore known from DE 196 08 056 C1 to connect the tool to an adapter at the end of the pipe conduit to be drawn in via a tensile pulling means in the form of a cable. This ensures that the pulling force of the tool is transmitted via the cable to the adapter, so that the pipe conduit is pushed together between tool and adapter.
As a result, the short pipes are fitted together more reliably and the stress to which the pipes are subjected is low.
Used in DE 196 08 056 C1 in order to tension the cable is a tensioning device which is supported on the adapter and shortens the cable via a hydraulic cylinder. Since the end of the last pipe is located inside the starting pit, the tensioning device must consequently also be arranged in this pit.
If the pipe has been drawn in over the length of a short pipe, a further short pipe has to be integrated in the combination. To this end, the tensioning device is released, the further short pipe is slipped onto the cable, the adapter is fastened to the rear end of the further short pipe, and the cable is shortened again. This procedure is extremely labor-intensive and time-consuming. In addition, the tensioning device, which is large and heavy on account of the forces to be applied, must be displaced inside the starting pit every time by at least the length of the short pipe.